Fuel pressure with 440's - Honda Prelude Forum

98preludesh · 07-01-2002, 04:52 PM

I just got done installing my new RC 440's along with the AEM fuel rail and regulator. My question is, what is a good idle, static and max fuel pressures??? I also have a V-afc and currently pulling 40 at idle. Any suggestions would be appreciated.

bradboy · 07-02-2002, 08:43 AM

What are the settings on your VAFC? . I also use RC 440's but found 40psi static press. too high which causes the car to be very sluggish and hesitant at pre boost stages . I presently am running 28-30 static with Vafc leaned out to -10 from idle to 5000 rpm.

jnkoh · 07-02-2002, 12:24 PM

just a little info I read, supposedly the prelude fuel pump can support 400 crank hp at stock fuel pressure, raising it to 75 psi, it will only be able to support 200. I just read that in Honda tuning

95PRELUDEVTEC · 07-02-2002, 01:42 PM

what is the prelude stock idle fuel pressure suppose to be at? 35psi at idle?

schwett · 07-02-2002, 01:44 PM

i believe the spec range is 30-37psi with the fpr reading idle vacuum and 10 psi higher at static. i don't have my helms handy.

Quote:

Originally posted by 95PRELUDEVTEC
what is the prelude stock idle fuel pressure suppose to be at? 35psi at idle?

95PRELUDEVTEC · 07-02-2002, 11:47 PM

thanks!!!

98preludesh · 07-03-2002, 11:08 PM

Anybody know the formula for figuring out fuel pressures with bigger injectors???

schwett · 07-03-2002, 11:34 PM

fuel flow is sqrt (pressure/43) * injector size

so at 43 psi, a 290cc (stock) injector flows 290cc/min.
at 35, it flows 260. to get a 440cc injector to flor 260cc/min, you need about 15psi. that's too low though, the car will run very poorly if you could get it that low (you can't anyway.)

you need to shorten the pulse width, either directly with a standalone or PMS style unit, or indirectly with a map modifier like the EMS or VAFC.

Quote:

Originally posted by 98preludesh
Anybody know the formula for figuring out fuel pressures with bigger injectors???